Upright furnace assembly



Dec. 23, 1958 H. J. CUTLER UPRIGHT FURNACE ASSEMBLY 3 Sheets-Sheet 1 Filed July 225, 1956 INVENTOR. #EPM/JN tf C10/'L52' Dec. 23, 1958 H. J. cuTLER 2,865,364

UPRIGHT FURNACE ASSEMBLY Filed July 23, 195 C5 Sheets-Sheet 2 IN VEN TOR. j #MM/W J @an e 1 BY @yg @@Mmm A rroeA/Ey' Dec. 23, 1958 H J, @U1-LER 2,865,364

UPRIGHT FURNAGE ASSEMBLY Filed July 2s, 195s Y s sheets-'Sheet :5

Perl/2N o ANZ 70 KUBA/EE INVEN TOR. #5e/ww d. @am-E nited States Patent UPRIGrrr FURNACE ASSEMBLY Herman J. Cutler, Edmonds, Wash., assigner to La Salle Oil Burner Company, Inc., Seattle, Wash., a corporation of Washington Application July 23, 1956, Serial No. 599,573

3 Claims. (Cl. 12o-110) This invention relates to an automatic o-il-ired circulating-air furnace for heating of residences and similar small and compact spaces, especially where the oor space available for its installation is small. Each such furnace must have its functioning parts and controls conveniently accessible for inspection, adjustment and replacement, notwithstanding the compactness of the whole, yet the controls, in general, and all surrounding building structure, must be adequately insulated from overheating. The furnace assembly must be simple and inexpensive, yet reliable over long periods of continuous operation.

The furnace assembly of this invention is of a nature somewhat similar to that disclosed in the patent to W. L. Steele, No. 2,144,129 of January 17, 1939, in that it is a simplified and compact installation, and like Steele employs but one motor that drives both a blower and the oil pump, which blower circulates the air and supplies bled-olf air for combustion. lt differs from the Steele assembly in that the present furnace assembly is arranged with the blower, motor, and oil pump above the furnace body rather than alongside the same, whereby the whole assembly'is better suited for unit installation in houses which lack any basement or furnace room, and wherein the furnace must occupy the very minimum of floor space, and no more vertical space than that between the floor and the ceiling, so that it is frequently installed in a small closet and upon the general oor slab that serves as the foundation and floor of the building.

The present invention, then, aims at the provision of a furnace assembly having a minimum area in plan and of dimensions to lit into a wall between two studs of the building wall, but of a height not exceeding the normal wall height of such a building, within which limitations must be located and installed, for easy access, all functioning elements of the furnace, of the oil burner, of the circulating blower, and of the automatic controls. Furthermore, such a furnace assembly must have its several pa'rts adequately separated during operation, and properly heat-insulated but freely accessible for adjustment and servicing when necessary.

Furnaces of the `type indicated frequently do not employ duct work, but take in air from the general space within the building and discharge it into the same space. Most usually, because convection currents rise, such furnaces are arranged to take in cold air from the floor level and to discharge the hot air near the ceiling, but this has proven to be inefficient in heating, since the hot air tends to collect and stagnate near the ceiling, and the floors are always cool, and so in an elfort to heat the room down to a comfortable level near the floor, the upper part of the room is considerably overheated. By the present invention this is reversed, and the cooler air is intaken near the ceiling level and is discharged after heating near the floor level, wherefore it may rise after it has been blown into and distributed within the interior space, and so there will tend to be more nearly uniform distribution of heat at the various levels.

By reason of the driving of the circulating blower by 2,865,364 Patented Dec. 23, 1958 the same motor that drives the oil pump, it might be supposed that the blower would cease operation upon opening of the room thermostat, and would not resume operation until the thermostat recloses, calling for more heat. Actually, it is necessary that the blower resume operation to dissipate residual heat in the furnace body, and that the oil burner at such time by-pass all oil pumped back to the fuel tank, and that none be delivered to the burner tip. These ends are attained by known controls, rearranged to accomplish such ends. The controls, and their rearrangement, are not part of my invention, but the same are shown and will be described hereinafter, to enable full understanding of the invention.

The present invention aims also to produce a furnace assembly of the character indicated which shall be simple and relatively inexpensive, and thus especially suited for the requirements of low-cost housing.

With such objects in mind, and others as will appear hereinafter, the present invention comprises the novel furnace assembly as a whole, and the novel combination and arrangement of the individual parts thereof with relation to one another, all as shown in a preferred form in the accompanying drawings, and as will be explained in greater detail in this specification, and the novel features whereof will be defined in the appended claims.

Figure 1 is an isometric View broken away to illustrate the complete assembly in condition for operation.

Figure 2 is, in general, an axial sectional view through the assembly on a Vertical plane from front to rear, with front and rear walls removed.

Figure 3 is an elevational view of the assembly looking from the front, but with the front wall of the housing removed.

Figures 4 and 5 are transverse sectional views at the respective lines 4-4 and 5 5 of Figure 2.

Figure 6 is a detail isometric view showing the blast tube and associated parts in section, to illustrate the location and arrangement of the burner tip and its igniting means.

Figure 7 is a diagram of the oil pump and of the controls for the same and for the blower, and Afor the motor common to and driving both pump and blower.

The furnace assembly of this invention comprises, in general, a furnace body of appreciable vertical height but of slight cross-sectional area, having a ceramic lire pot at its bottom and a smoke stack leading laterally from its top, supported within but spaced from the walls and bottom of a sheet metal cabinet or housing; a blast tube entering from the front surrounds a burner nozzle, and conveys to the lire pot air bled off from the circulating air and conducted by an upright duct from the bleedof point above the furnace body. Air is circulated by a blower positioned above the furnace body and directing the circulating air, intaken at the top of the housing, downwardly about the furnace body, to exit at the bottom of the housing. The air for combustion is bled off by means of an air scoop leading to the upright duct previously mentioned, and positioned at the outlet from the blower. An electric motor is located adjacent the blower, above the furnace body, to drive the blower and also to drive the oil pump, and is kept cool by the downward movement of air within the housing.l Various controls are located within the housing and arranged in a special manner, all as will be described in detail hereinafter, and the housing is formed with an insulated vertical panel intermediate the furnace body and a removable front wall, whereby by locating the controls and electrical apparatus in the insulated space, they are protected from direct heat, yet are readily accessible.

The closed furnace body is indicated in general by the numeral 1, and includes a ceramic tire pot ll) of con` ventonal shape, located at its lowermost point and openascisse@ ing upwardly, and a smoke stack 11 leads from itsupper portion and laterally for connection to a flue. llntermediate the fire pot and the smoke stack 11 is the combustion space, designated in` Figure 2 by the numeral 12. All this is preferably a selfcontained subassembly ready for mounting within an enclosing ,l'iogusing.V VThe furnace body 1 may conveniently be of rectangular cross-- section as shown, although this is not material.

Surrounding the furnace body 1 is a housing, generally indicated by the numeral 2. This too may be of upright, rectangular cross-sectional form and is spaced at all points from the furnace body housed within it to define a heat'exchange space 20. Theho'using preferably consists of two opposite side wallsZl, a rear'wall 22, and a' removable front 4wall 23. ".It is, of course, closed at its' top'by atop platei24, and it` should also have a bottom plate 25. Certainof these walls,"asrequircd, are insulated to lessen'the conduction'of'heat through the `wall to closely surroundingstructure.

The furnace body '1"is supported within'the'housing '2 in a manner'suchthat'the tire-"pot 10, being the lowest part'of the'furnace body, is elevated appreciably above the floor' level,`or above thebottom 25 of the housing, to define a hot air chamber 26 at floor level. A horizontal partition 3, constituting a platform is supported within the housing 2 above the `top of the furnace body 1, andsufciently below the top 24'of the housing 2 to define a cold air chamber 30. n One of the walls of the housing`2, preferably the removable front wall 23, and, preferably in addition, the rear wall 22, is provided with registers orlouvers 27a and 27k, respectively admitting to the cold air chamber 30 and affording means for discharge from the hot air chamber h26.

The burner tip `4 is mounted in an aperture through the'furnace body 1 and its ceramic tire pot 10 to discharge into the latter, and it is surrounded at its projecting outer end by a blast tube 40, whichl projects into the space between the furnace body and' the removable front wall 23. 'Preferably anV extra panel 2S, which also maybe and preferably is insulated, is installed in an upright position between andspaced from each of the front wall 23 and the furnace body, and extending from the partition 3 downwardly toiabout the lowermost level of the furnace body. The space 28a between this panel ,28 and the'removablefront wall 23 may be completely sealed off'rfrom the air circulation space by a shelf 25a. `Thisshelf may, itself, constitute the support for the furnace body 1, or the lattermay and preferably is supported by U-shaped supports or brackets 15, from the oor directly. TheV outer end of the blast tube'40, within the space 28a, is'closed by a removablecap 4 1, whereby access may be had to the 'burner tip V4f and to the igniting spark means'therein, indicated at`42 (seeFigure 6).

A blower 5 iseprovidedfor forced circulation of air through the housing, for the air'movement'is 'counter to convection currents. This blower is mounted or supported from the partition 3, preferably being located in the cold air chamber 30. lts inlet, being open to that chamber', takes in air admitted through the upper register 27a, andthe blower outlet communicates (by way of an opening 50 in the partition 3) with the heat exchange space 2.0 between the furnace body 1 and the housing 2. A motor M is provided for driving'the blower 5, and this too can be supported upon the partition 3. There must also be an oil pump, which is indicated generally at 43, and which in practice may include (Figure 7) a suction pump 43a and a pressure pumpi 43h. This also can be supported upon the partition"3,;'in"such' manner that the motor M drives both the'blower Sand'the `oil pumpV by means of a commonbelt59. ,An oil pressure line 44 extends from the output of' the oilpump 43 (or 43h) Yto the blast tube 40 and thence to the burner tip d. An oil feedline 45, as Vis customary,- will"also extend to the oil pump 43` (or 43a), and a return line 46, also customary, will return to the tank (not'shown) all oil not '4 delivered tothe burner tip or to the pressure pump 43h for delivery to such burner tip 4.

As in the Steele patent mentioned above, no separate blower is provided for supplying combustion air to the burner tip. Instead, a portion of the air is bled off from the circulating air supply and is conveyed by a suitable duct to the blast tube 40, and thence past the burner tip into the fire pot. In the present arrangement however, differing from the Steele arrangement, it is necessary to provide a fairly extensive and lengthy duct, and one that is conveniently accessible when this is necessai-y. Such a duct is indicated in general by the numeral 6, and comprises, in effect, an air scoop 60 for interposition within the air discharge aperture from the blower 5, anda channel-shaped duct 6 extending downwardly from the scoop for connection to the blast tube 4@ whence air is directed around the burner tip 4 and into the fire pot 10. The channel ofthe duct 6 is open to the fro-nt, and the channel-shaped' form of the scoop 649 is open to the top, these openv sides being closed respectively and to the`extent necessary, by the panel 2S and by the partition 3. Thus, upon removal of the panel or partition 28, the air duct is freely opened and accessible, yet is adequately closed when the panel 28 is in place. The duct 6 may be insulated if desired, since it extends downwardly alongside,'but not in'contact with, the furnace body 1.

lt being desirable to regulate the volume of air admitted thro-ugh the blast tube, in correct ratio to the volumetric rate of the oil supplied to the burner tip, this is conveniently done by providing a damper 61 in the duct 6, mounted upon a spindle 62 pivoted in the panel 28 and provided with a handle 63 within the space 28a, by means of which the position'of the damper 61 in its duct may be regulated.

Such a burner is provided with various automatic controls, a transformer, condenser, junction boxes, etc., and all these, to the greatest extent possible, should be so located that they are readily accessible, and so that they are not harmfully affected by the heat of the furnace body. By locating them so Vfar as possible in the space 28a between the removable frontwall 23 and the insulated upright panel 28, such control s,{etc., may be readily accessible and yet are' protected by the insulated panel 28 from the heat. Varioussuch controls are shown and indicated generallybytheletter C, but they may be largely of'known characterand` arrangement, and it is not necessary to describe lthem in detail, with certain exceptions hereinafter explained. `An inspection pipe 29 permits'inspection of the character of the flame within thefirepot. n v n ,A p

Because `the space 28a, if closed over long periods of operation, might tend` to heat up to an vundesirable ternperature despite the insulation of the panel ,28, louvered apertures 23a in the removable front wall 23 are provided at top and bottom respectively of this space, for passage of convection .currents through the space 28a to cool it and the installations therein. p

It has been explained that the blower must operate after cut-off of oil to the burner tip, in order to dissipate residual heat in the furnace body, yet when vthe thermostat calls for heat, the oil pump must commence to operate normally, as the blower vcommences its operation. All this must occur notwithstanding the driving vof the single blower 5 and the oil pump43by the common driving motor M. Such operation is accomplished by certain controls which in` essence are normal controls in such an installation, but slightlyrearranged. None of this is part of my invention, andis not claimed by me.

The oil pump is provided withan'internal by-pass passage 47, havinga solenoidvalve 48 biased to remain open, for return of all oil pumped to the tank via pipe 46, but movable to closed position when its solenoid 49 is energized, for delivery of pumped oil to the burner tip. Such a by-pass valve is normal, except that normally it is biased to close, and is opened only by energization of the solenoid. The electrical control circuit is substantially normal, with the exception just noted, and will be best understood by describing its operation.

When the room thermostat T calls for heat, the starting circuit is established through relay coil 71, safety switch heater 72, safety switch 7, and back to the thermostat T. Relay coil 71, thus energized, closes its low-volt age contacts 73 and line-voltage contacts 74. When 73 and 74 close, the ignitionat 75 co-mes on, the oil valve 48 closes, and the low-voltage circuit is established through relay coil 76 and contacts 74. Relay coil 76, thus energized, closes its contacts 77 and 78. When 78 closes, the line-voltage circuit is completed to mo-tor M, which then starts. The oil valve 48 having previously been closed, delivery of oil to the burner tip commences with energization of motor M. v

If flame is not established, the stack temperature will not rise enough to close Pyrostat hot contacts 79a (the Pyrostat 79 being projected into the furnace body) before the end of the safety switch timing period. The current through the safety switch heater 72 will therefore cause the safety switch 7 to lock out, or open. Normally, however, the furnace temperature will rise, first closing Pyrostat hot contacts 79a and then 79b. When 79a closes, the safety switch heater 72 is shunted out, and the running circuits are completed.

When the thermostat T is satisfied, its contacts open, breaking the low-voltage circuit through relay coil 71, hot contact 79a, safety switch 7, and thermostat. Deenergizing the relay coil 71 causes contacts 73 and 74 to open. When 74 opens, the line-voltage circuit is broken to ignition at 75 and to the oil valve solenoid at 49. The oil valve will open, thereafter by-passing all oil back to the tank, and the ignition will cut off.

The motor M continues to operate, to provide a postcycle purge, for the purpose of dissipating residual heat, because the motor-relay holding circuit is maintained through relay coil 76, hot contact 79h, and relay contacts 77. The motor will continue to run untilthe combustion chamber temperature drops to a given low value, enough to cause the Pyrostat hot contact 79b to open, breaking the motor-relay holding circuit. During none of this time 'is there any delivery of oil, although the blower is running.

A high limit control switch at C2 in the line closes at a given low value and opens at a given higher value, so that whenever air in the space 28a, wherein the control C2 is installed, reaches the upper limit of temperature, this limit control C2 opens and shuts off everything.

By the construction described', there is provided a compact upright furnace of good eiiiciency, with forced circulation in a direction which affords the best heating etliciency for the space to be heated, with all parts accessible when necessary, and protected against undue heat. The furnace assembly, notwithstanding its close proximity to the wall structure, will not heat the latter beyond an acceptable temperature, even during prolonged operation. Operating parts are reduced to a minimum, and the installation is of reasonable cost, yet is reliable over long periods of time.

I claim:

l. A unitary furnace assembly comprising an upright housing having a separate, closable and openable front wall for access to the space within the housing immediately behind said front wall, the housing being adapted to be supported from the floor, and an upright furnace body supported within the housing with its bottom above the oor level and its top below the upper end of the housing, the housing and furnace body being of relative sizes and relatively disposed to define a hot air chamber at floor level beneath the furnace body and a generally upright heat exchange space surrounding the furnace body and between the latter and the housing, said heat exchange space communicating at its bottom with the hot air chamber; an upright panel spaced intermediate the front wall of the housing and the furnace body to define an upright control space generally separate from the heat exchange space; a platform supported within the housing in spaced relation above the furnace body and below the top of the housing to define an uppermost cold air chamber, the housing having registers admitting air to the cold air chamber and for discharge of such air from the hot air chamber; the furnace body including a fire pot at its lower end, a smoke stack leading from its upper end, and an intermediate combustion space; an oil pump, a blower, and a motor connected to drive the pump and the blower, all supported from said platform, the blower inlet being open to the cold air chamber and its outlet opening discharging through said platform to the heat exchange space; a blast tube within but elo-sed off from the heat exchange space, projecting at its outer end into said control space, and connected for discharge within the re pot; a cap closing the outer end of the blast tube and accessible from within the control space; an oil burner tip within said blast tube; an oil line extending between the oil pump and said burner tip; an air duct generally of channel form located within the heat exchange space immediately behind and normally closed at its open side by said upright panel, said air duct including an air scoop disposed immediately below the platform at the blower outlet opening of a size and shape relative to such outlet opening to intercept a portion of the discharged air, said air duct extending downwardly from said scoop within the heat exchange space past the furnace body to said blast tube to supply air into the blast tube and past the burner tip for combustion; control devices operatively connected to the furnace assembly; and control means operatively connected to said control devices and located in and accessible from within the control space.

2. A unitary furnace assembly as in claim l, including a control damper disposed in said air duct, a spindle journaled in the upright panel and mounting said control damper to vary the air volume moving through the air duct, and a handle carried upon said spindle for controlling said damper, located in said control space.

3. A unitary furnace assembly comprising an upright housing including a front wall closable and openable for access to the space immediately therewithin, the housing being adapted to be supported from the flo-or, and an upright furnace body supported within the housing with its bottom above the Hoor level and its top below the upper end of the housing, the housing and furnace body being of relative sizes and relatively disposed to define a hot air chamber at iioor level beneath the furnace body and a generally upright heat exchange space surrounding the furnace body and between the latter and the housing, said heat exchange space communicating at its bottom with the hot air chamber; a platform supported within the housing in spaced relation above the furnace body and below the top of the housing to define an uppermost cold air chamber, the housing having registers admitting air to the cold air chamber and for emission of such air from the hot air chamber; the furnace body including a fire pot in its lower portion; a blast tube admitting to ,said fire pot and projecting from the furnace body into the heat exchange space; an oil pump, a blower, and a motor connected to drive the pump and the blower, all supported from said platform, the blower inlet being open to the cold air chamber and its outlet opening discharging through said platform to the heat exchange space; an oil Aburner tip within said blast tube and an oil line extending between the pump and the burner tip; an upright panel removably supported intermediate the front wall o f the housing and the furnace body to define an upright space within but separate from the heat exchange space and accessible by opening the ,front wall, ,the blast tube prof eciting'intol'said'separate space; andY an' air duct generally of channel form disposed within'rthe heat exchange space with its open side forwardly'and located immediately behind said 4upright'panel to be closed by the latter, said air duct including an air scoop disposed immediately below the platform atlthe blower otlet opening of a size and shape relative Ito such outlet opening to intercept a portion of the discharged air, said air duct extending downwardly to and connected for discharge within said blast tubeito supply air for combustion.

f References Cited in the yfile 'of this patent UNITED STATES "PATENTS Anderson etal Marf26,

Woolery -Iune 25,

Holthouse Dec. 9,

Horn 'Apr. 22,

Jaye et al. 5--- Nov. 10,

FOREIGN rPATENTS France Oct. 2l, 

